How important is Optimal Debulking?

Debulking Predicts Survival in Recurrent Ovarian Cancer
The success of primary surgery for ovarian cancer predicted progression-free and overall survival in recurrent disease in patients with at least a 12-month platinum-free interval, data from three large clinical trials showed.

Survival decreased significantly as the residual mass increased from microscopic to greater than 10 mm. The effect of the completeness of initial surgery remained significant in an adjusted analysis.

"Complete surgical debulking significantly improves prognosis in advanced ovarian cancer, not only at primary diagnosis but also after disease recurrence in platinum-sensitive patients experiencing relapse later than 12 months after primary therapy," Sven Mahner, MD, of University Medical Center Hamburg-Eppendorf in Hamburg, Germany, reported at the American Society of Clinical Oncology meeting.

Optimal surgical debulking has well-documented prognostic value at initial diagnosis of advanced ovarian cancer. Whether the prognostic potential extends to recurrent or relapsed disease remained unclear.

To determine the impact of initial surgery on recurrent or relapsed ovarian cancer, Mahner and colleagues performed a meta-analysis of three prospective clinical trials that evaluated platinum-taxane chemotherapy in advanced disease.

Using data from original case-report forms, investigators stratified patients on the basis of residual tumor size: microscopic, 1 to 10 mm, and >10 mm. The principal outcomes were progression-free survival (PFS) and overall survival, calculated from the day of randomization. Time to recurrence was calculated from the last day platinum chemotherapy was administered or the last day of the sixth course of chemotherapy in patients who received more than six courses.

The studies involved a total of 3,388 patients, of whom 3,126 were included in the analysis. The patients had a median PFS of 18 months and a median overall survival of 44 months.

Surgical outcome did not affect PFS or overall survival in patients whose disease recurred within 12 months after completing chemotherapy. In contrast, the completeness of surgical debulking had a significant impact on the survival of patients with a platinum-free interval greater than 12 months.

Median PFS decreased from 14.3 to 12.6 to 12.0 months as residual tumor size increased from microscopic, 1 to 10 mm, and >10 mm (P=0.0265). Median overall survival decreased from 28.1 to 22.7 to 20.2 months as the amount of residual tumor increased (P=0.0079). The differences remained significant after adjustment for time to recurrence as a continuous variable to rule out the effect of different time intervals before relapse.

"Our analysis represents the first study investigating the relevance of primary surgical outcome for survival after recurrence in ovarian cancer," Mahner and colleagues concluded in their poster presentation. "Our data show that the prognostic importance of initial surgery extends beyond initial treatment to recurrent disease, particularly for patients who have a platinum-free interval of more than 12 months."

http://www.medpagetoday.com/MeetingCoverage/ASCO/20513